Patient positioning device of a panoramic dental x-ray apparatus

ABSTRACT

A positioning device for positioning a patient when being radiographed with a panorama X-ray machine  10 , comprising a retainer  18  disposed in a fixed direction relative to the X-ray apparatus  10  and a variable positioner connected thereto, for example a bite block  19  or a support, has a longitudinal guide  20  on the retainer  18  for guiding said positioner  19  such that said positioner  19  is guided in said retainer  18  for vertical adjustment in the longitudinal direction.

TECHNICAL FIELD

The invention relates to a positioning device for correct positioning ofa patient when being radiographed with a panorama X-ray imaging device.

PRIOR ART

When a panorama X-ray camera is used, the operator must position thepatient prior to take the radiograph and optionally also during theradiographing procedure. This is accomplished with a positioning devicecomprises a bite block or a positioning support. For different types ofradiographs, the positioner must be interchanged in order to permitpositioning at different levels. As a result of the change, despite allprecautionary measures, the situation may arise that a bite blockunsuitable for radiographing is used. Furthermore, for patients havingno front teeth, other positioning supports may be necessary, such as asubnasal positioning support that the patient does not bite on butrather against which he rests.

DE 36 09 260 A1 discloses a panorama X-ray device for producing panoramaX-ray radiographs and having three exchangeable bite blocks. A firstbite block is provided for so-called standard radiographs, a second biteblock for so-called sinus and mandibular radiographs. A third bite blockis also suitable for mandibular radiographs but for an X-ray beam comingfrom a different direction. The bite blocks have sockets which are ofthe same design so that one or other of the bite blocks can be insertedinto a retaining guide shaft of a support member. In order todistinguish the bite blocks from each other, they have differentidentification marks, particularly in the form of color-code marks.

DE 35 30 234 A1 discloses a bite block which is disposed on thevertically adjustable support member. The support member is designed asan eccentrically mounted roller and has two reception holes for thesupport member, which holes are provided for a standard radiograph andfor a sinus and mandibular radiograph.

DE 102 50 005 A1 discloses a bite-block system which comprises a swivelplate mounted on a retainer. This does not allow for any heightadjustment of the bite block, however, since only the angle ofinclination of the chewing plane is to be considered or the X-ray devicehas to be adjusted to a pre-assigned value.

However, it sometimes occurs that in the predefined positions whenperforming transverse tomography (TSA) of the molars, the ramus, i.e.the lower edge of the mandible is not completely imaged.

Radiographs in the central part of the face, i.e. above the upper jaware also sometimes incomplete, especially that of the mandibular joint.

WO 02/086619 A1 discloses a tomographic device for dental tomosynthesisin which the bite block is affixed to an articulated arm and said armengages a locking bolt when the patient is in the correct position. Thedisadvantage here is that no standard positions can be set.

It is an object of the invention, as characterized in the claims, toprovide an apparatus for the correct positioning of a patient when beingradiographed with a medical panorama X-ray imaging device, permittingsimple and firm positioning of a patient.

SUMMARY OF THE INVENTION

This object is achieved according to the invention by the positioningdevice defined in claim 1. Advantageous developments of the inventionare the subject matter of the subordinate claims.

The advantage gained is that the operator does not have to change thepositioners for different radiographs but only carries out verticaladjustment. Instead of the three bite blocks used hitherto, i.e. onestandard bite element and two bite elements for the midfacialradiographs and accordingly three supporting elements, a single biteblock and a single supporting element may be used. This reduces the riskof omitting to change the positioner for body size adjustment.

Other advantageous variants, features and details of the invention aredisclosed in the dependent claims, the description of the exemplaryembodiments, and the drawings.

Advantageously, the retainer has a socket for fixation on a support ofthe X-ray device and the longitudinal guide is set axially at a distancefrom the socket, advantageously in the direction toward the patient.This makes it possible to move the positioner past the carrier duringlongitudinal displacement.

Advantageously, detents corresponding to a normal jaw can be providedfor the positioner in the longitudinal guide for predefined standardlevels. This permits rapid and secure fixation at the correct level.

In the longitudinal guide for fixation of the positioner, fixing meansare advantageously provided in positions lying outside of the detents.By such means it is possible to effect individual adaptations to theanatomical peculiarities of the patient.

Advantageously, the standard levels of the positioner are coded on thepositioner by marks such that incorrect settings are largely obviated.

Marks that are clearly distinguishable from each other by color areparticularly suitable.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is explained with reference to an exemplary embodiment. Inthe drawings:

FIG. 1 shows a schematic representation of a panorama X-ray imagingdevice comprising a positioning device comprising a positioner in theform of a bite block or a supporting block,

FIG. 2 shows a positioning device comprising a bite block,

FIG. 3 shows a positioning device comprising a supporting block.

DESCRIPTION OF EMBODIMENTS

FIG. 1 is a schematic representation of a panorama X-ray imaging device10 in which a swiveling unit 12 disposed on a column 11 carries aradiation source 13 and a detector camera 14 located opposite it. On thecolumn 11, in addition, there is a carrier 15 comprising a holder 16 fora positioning device 17 comprising a retainer 18 for a positioner 19that is vertically adjustable relative to the retainer 18.

Adaptation of the device 10 to the body size of the patient isaccomplished by adjustment of the rotating unit 12, if necessarytogether with vertical adjustment of the support 15. Adaptation for thetype of radiograph is accomplished by adjustment of the positioningdevice 17.

FIG. 2 is a perspective view of the positioning device 17 according toan exemplary embodiment of the invention comprising a bite block 19. Thepositioning device 17 has a retainer 18 on which the bite block 19 isguided longitudinally by means of a longitudinal guide 20. The biteblock 19 also has a guided adjusting segment 19.1 and a bite plate 19.2disposed at an angle thereto.

The longitudinal guide 20 is axially spaced from a socket 21 relative tothe patient and it at least partially encircles the adjusting segment19.1 of the bite block 19. The adjusting segment 19.1 contains detentsfor arresting it in the longitudinal guide 20 at predefined standardheights suitable for a normal jaw. In order to produce a definitelocking position, a spring-loaded tongue on the longitudinal guide 20can engage a groove 25, 26 in the adjusting segment. Intermediatepositions are not usually required but may be provided by means of aclamping mechanism, which causes two parts on the bite block 19 to beupwardly or downwardly pushed against the retainer 18.

On the adjusting segment 19.1 there are provided three marks 22 to 24.1as well as one mark 24.2 at different levels, to which the lockingpositions of the adjusting segment 19.1 in the longitudinal guide maycorrespond. The marks 22 to 24.2 may correspond to the differentstandard bite elements used hitherto for the standard radiograph, forthe sinus and mandibular radiographs and for other mandibularradiographs produced from a different X-raying direction.

The top mark 22 serves for positioning the patient for creating atransversal tomograph of the midface, also called a midfacial radiographor sinus radiograph, and of the upper jaw, also called a maxillarytomograph.

The second highest mark 23 serves for positioning the patient for makinga mandibular radiograph. In addition, in this position a midfacialradiograph or sinus radiograph and a maxillary radiograph may also betaken. These radiographs are also transverse tomographs.

The second lowest mark 24.1 serves for positioning the patient fortaking a standard panorama tomograph as well as other standardradiographs. In addition, in this position a transverse tomograph of themandible can also be taken, also called a mandibular radiograph.

The bottom mark 24.2 serves for positioning the patient for taking atransverse tomograph of the mandible in an even lower position.

To prevent the risk of incorrect positioning, the marks 22 to 24.2 maybe distinguished from each other by color coding.

FIG. 3 shows a subnasal support 29 for patients having no front teeth,which has an adjusting segment 29.1 that is somewhat longer than in thecase of the bite block 19 shown in FIG. 2 so that a supporting segment29.2 is higher than the bite block 19.2. The supporting piece 29 is alsocolor coded and corresponds in its connection zone to the bite block 19shown in FIG. 2 so that it can be inserted into the holder 20 in placeof the bite block 19.

1. A positioning device for positioning a patient in a panorama X-raymachine (10) comprising a retainer (18) disposed in a fixed directionrelative to the X-ray apparatus (10) and a variable positioner (19, 29)connected thereto, characterized in that said retainer (18) has alongitudinal guide (20) for the positioner (19, 29) to enable verticaladjustment of said positioner (19, 29) relative to said retainer (18).2. The positioning device according to claim 1, characterized in thatsaid positioner is a bite block (19) or a support (29).
 3. Thepositioning device according to claim 1 or claim 2, characterized inthat said retainer (18) a socket (21) adapted for attachment to acarrier (15) of said X-ray apparatus (10) and that said longitudinalguide (20) is set at an axial distance from said socket (21).
 4. Thepositioning device according to any one of claims 1 to 3, characterizedin that detents are provided in said positioner (19, 29) to enablearrestment thereof in said longitudinal guide (20) at predefinedstandard levels corresponding to a normal jaw.
 5. The positioning deviceaccording to claim 4, characterized in that locking means are providedin said longitudinal guide (15) for fixation of said positioner (19, 29)in positions outside of said detents.
 6. The positioning deviceaccording to any one of claims 4 and 5, characterized in that differentstandard levels are marked on said positioner (19, 29) by means of marks(22-24.2).
 7. The positioning device according to claim 6, characterizedin that said marks (22-24.2) are clearly distinguishable from each otherby color coding.